Low frequency bilateral communication over distributed power lines

• US 7,224,740 B2
• Filed: 02/28/2005
• Issued: 05/29/2007
• Est. Priority Date: 09/23/1997
• Status: Expired due to Fees

• Current Assignee: Hunt Techonologies Incorporated (Landis+Gyr Group AG)
• Original Assignee: Hunt Techonologies Incorporated (Landis+Gyr Group AG)
• Inventors: Hunt, Paul C.
• Primary Examiner(s): Bayard; Emmanuel
• Assistant Examiner(s): WILLIAMS, LAWRENCE B
• Application Number:
  US11/068,496
• Publication Number:
  US 20050231039A1
• Time in Patent Office: 820 Days
• Field of Search: 375/219, 375/220, 375/259, 340/310.01, 340/313, 340/310.02, 340/870
• US Class Current: 375/259
• CPC Class Codes: H02J 13/00009 using pulsed signals
• CPC Class Codes: H02J 13/0001 using modification of a parameter of the network power signal
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H04B 2203/542 using zero crossing information
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: Y04S 10/52 Outage or fault management, e.g. fault detection or location

Abstract

A system and method for providing full-duplex data communications between an electric power distribution station and a power consumer via the power distribution line providing electric power is provided. A first information transmitter, coupled to the power distribution circuit, provides first information signals concurrently with the power signal to the power consumer via the power distribution line. A first information receiver, coupled to a power consumer device powered by the electrical power signal, receives the first information signals via the electric power distribution line. A second information transmitter coupled to the power consumer device provides second information signals concurrently with the electrical power signal. A second information receiver, coupled to the power distribution circuit, receives the second information signals via the electric power distribution line. The information signals transmitted on the power distribution line can be transmitted at a frequency lower than the frequency of the transmitted power signal.

Claims

1. A full-duplex communications system for transmitting information, comprising:

an electric power distribution line to transmit an electrical power signal;

a power distribution circuit coupled to the electric power distribution line to provide the electrical power signal to a power consumer via the electric power distribution line, the electric power signal being transformed to a voltage level useable by the power consumer by a transformer;

a first information transmitter coupled to the power distribution circuit to provide first information signals concurrently with the electric power signal to the power consumer via the electric power distribution line, the first information signals passing through the transformer, the first information transmitter comprising,

a first carrier frequency signal generator configured to generate a first carrier frequency signal using a first stable input signal from at least one of the following;

the electric power signal, a satellite clock signal, an atomic clock signal, and an internally mounted circuit,

a first signal inversion circuit configured to invert every other half-period of the first carrier frequency signal, and

a first signal generator circuit configured to modulate the first information signals onto the electrical power distribution line using the first carrier frequency signal;

a first information receiver, coupled to a power consumer device powered by the electrical power signal, to receive the first information signals via the electric power distribution line;

a second information transmitter coupled to the power consumer device to provide second information signals concurrently with the electrical power signal via the electric power distribution line, the second information signals passing through the transformer, the second information transmitter comprising,

a second carrier frequency signal generator configured to generate a second carrier frequency signal using a second stable input signal from at least one of the following;

the electric power signal, the satellite clock signal, the atomic clock signal, and the internally mounted circuit;

a second signal inversion circuit configured to invert every other half-period of the second carrier frequency signal, and

a second signal generator circuit configured to modulate the second information signals onto the electrical power distribution line using the second carrier frequency signal; and

a second information receiver coupled to the power distribution circuit to receive the second information signals via the electric power distribution line,

whereby full-duplex communication between the power distribution circuit and the power consumer is accomplished via the electric power distribution line.

2. The system of claim 1, wherein the satellite clock signal is received from a global positioning system.

3. The system of claim 1, wherein the internally mounted circuit uses a frequency locked loop system.

4. The system of claim 1, wherein the internally mounted circuit uses a phase locked loop system.

5. The system of claim 1, wherein the first information signals are configured to control a device.

6. The system of claim 1, wherein the first signal generator circuit is configured to modulate the first information signals at a frequency that is an integer value of one-half the period of the first carrier frequency.

7. The system of claim 1, wherein the second signal generator circuit is configured to modulate the second information signals at a frequency that is an integer value of one-half the period of the second carrier frequency.

8. The system of claim 1, wherein the first signal generator circuit is configured to modulate using one of the following:

a frequency modulation, an amplitude modulation, a phase modulation, and a combination of frequency and phase modulation.

9. The system of claim 1, wherein the second signal generator circuit is configured to modulate using one of the following:

a frequency modulation, an amplitude modulation, a phase modulation, and a combination of frequency and phase modulation.

10. The system of claim 1, wherein the first information receiver comprises a first digital signal processor configured to provide at least one of the following:

demodulation and filtering.

11. The system of claim 1, wherein the second information receiver comprises a second digital signal processor configured to provide at least one of the following:

demodulation and filtering.

12. The system of claim 1, wherein the first information transmitter further comprises a first zero cross-over sensing circuit to anticipate the zero cross-over of the electric power signal.

13. The system of claim 1, wherein the second information transmitter further comprises a second zero cross-over sensing circuit to anticipate the zero cross-over of the electric power signal.

14. The system of claim 1, wherein the first information transmitter further comprises a first phase-shifting circuit to shift a phase of every half-period of the carrier frequency signal.

15. A full-duplex communications system for transmitting information, comprising:

an electric power distribution line to transmit an electrical power signal;

a power distribution circuit coupled to the electric power distribution line to provide the electrical power signal to a power consumer via the electric power distribution line, the electric power signal being transformed to a voltage level useable by the power consumer by a transformer;

a first information transmitter coupled in series with a neutral connection of the power distribution circuit to provide first information signals concurrently with the electric power signal to the power consumer via the electric power distribution line, the first information signals passing through the transformer, the first information transmitter comprising,

a first carrier frequency signal generator configured to generate a first carrier frequency signal using a first stable input signal from at least one of the following;

the electric power signal, a satellite clock signal, an atomic clock signal, and an internally mounted circuit,

a first signal inversion circuit configured to invert every other half-period of the first carrier frequency signal, and

a first signal generator circuit configured to modulate the first information signals onto the electrical power distribution line using the first carrier frequency signal;

at least one protection module coupled between the neutral connection of the power distribution circuit and the first information transmitter, wherein the protection module having a ground connection can recognize an open-circuit between the neutral connection of the power distribution circuit and the first information transmitter, and ground the neutral connection of the power distribution circuit;

a first information receiver, coupled to a power consumer device powered by the electrical power signal, to receive the first information signals via the electric power distribution line;

a second information transmitter coupled to the power consumer device to provide a second information signal concurrently with the electrical power signal via the electric power distribution line, the second information signals passing through the transformer, the second information transmitter comprising,

a second carrier frequency signal generator configured to generate a second carrier frequency signal using a second stable input signal from at least one of the following;

the electric power signal, the satellite clock signal, the atomic clock signal, and the internally mounted circuit,

a second signal inversion circuit configured to invert every other half-period of the second carrier frequency signal, and

a second signal generator circuit configured to modulate the second information signals onto the electrical power distribution line using the second carrier frequency signal; and

a second information receiver coupled to the power distribution circuit to receive the second information signals via the electric power distribution line,

whereby full duplex communication between the power distribution circuit and the power consumer is accomplished via the electric power distribution line.

16. The system of claim 15, wherein the at least one protection module is configured to carry at least a maximum current capable of being carried on the neutral connection of the electric power distribution line.

17. The system of claim 15, wherein the at least one protection module comprises:

a conductive restraining device coupled between the neutral connection of the power distribution circuit and the ground connection, the conductive restraining device being open and separating the neutral connection of the power distribution circuit and the ground connection until a voltage at the neutral connection is sufficiently high to pass a current through a voltage threshold device causing the conductive restraining device to close; and

the voltage threshold device having properties such that the voltage threshold device'"'"'s resistance changes as the voltage at the neutral connection changes according to at least one of the following;

the voltage threshold device'"'"'s resistance diminishing at a faster rate than the voltage change at the neutral connection, the voltage threshold device'"'"'s resistance diminishing at a same rate than the voltage change at the neutral connection, the voltage threshold device'"'"'s resistance diminishing non-linear to the voltage change at the neutral connection, and a switched grounding device, switching the ground connection to a shorted connection at a maximum threshold voltage and to an open connection at a minimum threshold voltage.

18. The system of claim 15, wherein the first signal generator circuit is configured to modulate using one of the following:

a frequency modulation, an amplitude modulation, a phase modulation, and a combination of frequency and phase modulation.

19. The system of claim 15, wherein the first information receiver comprises a first digital signal processor to provide at least one of the following:

demodulation and filtering.

20. A communication method for communicating between an electric power provider and an electric power consumer using an electric power distribution line comprising:

providing an electric power signal to the electric power consumer through an electric power distribution circuit, the electric power signal being transformed to a voltage level useable by the electric power consumer by a transformer;

transmitting a first full-duplex communications signal through the electric power distribution circuit concurrently with the electric power signal using a first signal transmitter, the first signal transmitter coupled to the electric power distribution circuit, the first signal transmitter comprising,

a first signal inversion circuit configured to invert every nth half-period of a carrier frequency signal, and

a first signal generator circuit configured to modulate the first full-duplex communications signal onto the electric power distribution circuit, the first signal generator comprising a carrier frequency signal generator circuit configured to generate the carrier frequency signal using a first stable input signal from at least one of the following;

the electric power signal, a satellite clock signal, an atomic clock signal, and an internal circuit;

receiving the first full-duplex communications signal through the electric power distribution circuit using a first signal receiver, the first signal receiver coupled to the electric power distribution circuit,

transmitting a second full-duplex communications signal through the electric power distribution circuit concurrently with the electric power signal using a second signal transmitter, the second signal transmitter coupled with the electric power distribution circuit, the second signal transmitter comprising,

a second signal inversion circuit configured to invert every nth half-period of the carrier frequency signal, and

a second signal generator circuit configured to modulate the second full-duplex communications signal onto the electric power distribution circuit, the second signal generator comprising a second carrier frequency signal generator configured to generate the carrier frequency signal using a second stable input signal from at least one of the following;

the electric power signal, the satellite clock signal, the atomic clock signal, and the internal circuit; and

receiving the second full-duplex communications signal through the electric power distribution circuit using a second signal receiver, the second signal receiver coupled to the electric power distribution circuit.